Method for treating abdominal aortic aneurysms using a combined laparoscopic/open and endovascular technique

ABSTRACT

A method for releasing an aortic prosthesis includes positioning an introducer in femoral arteries of a patient. Guiding balloon catheters are positioned through the introducers to locate balloons thereof in terminal parts of common iliac arteries. The proximal aorta is clamped, balloons of the guiding catheters are inflated, and the aorta is opened for outside access. Distal ends of releasing balloon catheters are threaded through the guiding catheters and are recovered outside the patient through the introducers. Distal ends of the releasing catheters are connected to distal portions of the prosthesis, which is moved by the catheters until distal portions thereof contact the guiding catheters. The proximal part of the prosthesis is sutured to the aorta. The balloons of the releasing catheters are inflated to fix the distal portions of the prosthesis. Balloons are deflated, catheters are removed, the aorta is sutured, and the introducers are removed.

CROSS-REFERENCE TO RELATED APPLICATION

This application is a divisional of U.S. patent application Ser. No.10/718,315, filed Nov. 20, 2003, which claimed priority, under 35 U.S.C.§ 119, to Italian Patent Application No. RM 2002 A 000596, filed Nov.27, 2002, the entire disclosures of which are hereby incorporated hereinby reference in their entireties.

STATEMENT REGARDING FEDERALLY SPONSORED RESEARCH OR DEVELOPMENT

n/a

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a method for implanting a vascularprosthesis for the treatment of abdominal aortic aneurysms, using acombined laparoscopic/open and endovascular technique. The presentinvention also relates to a delivery system for the release of aprosthesis fitted with anchoring stents, such as the above-mentionedvascular prosthesis or other prostheses.

Aneurysm of the abdominal aorta is a degenerative disease of the vesselthat results in dilation and, sometimes, fatal rupture. In the past,when this disease was diagnosed, open surgery was generally performed torepair the damaged vascular section and, therefore, to prevent ruptureof the vessel.

Traditionally, open surgery includes resection of the aneurysm and theimplantation of a bifurcated prosthesis. The bifurcated prosthesis ismade of a suitable tissue, such as polytetrafluoroethylene (PTFE) orDACRON®, which is the trade name of a particular polyester fiber fromDUPONT®. The approach is through a large abdominal incision, opening theaneurysm after upstream and downstream closure (clamping) of the aorta(consequently preventing circulation in the lower part of the body forthe duration of the procedure), suturing the holes of the lumbararteries from inside the abdominal aorta, and suturing of theabovementioned prosthesis to the healthy parts. This procedure, whichhas been in use for decades, is particularly invasive, is associatedwith long convalescence and major general risks, and is, undoubtedly, along-lasting procedure with full rehabilitation of the patient.

An endovascular technique, providing for the application of anendoprosthesis, that is, a prosthesis inserted within the vessels, withaccess from the inguinal arteries, and, therefore, without “opening” ofthe abdomen, was introduced some ten years ago. Such a prosthesisexpands within the aneurysm, bearing against the healthy parts to whichit is fixed through the effect of the radial force exerted by stents, orexpandable metal retaining members, which are sutured or fixed to theconventional tissue prosthesis (DACRON® or PTFE). This is a very clearexample of mini-invasive surgery, but, unfortunately, there are limitsto its application and inherent problems.

The limitations upon the endovascular technique are determined by theanatomical conformation of the part referred to as the proximal neck ofthe aorta, that is, the healthy cranial part against which theendoprosthesis is supported. In fact, it is specifically theunsuitability of an excessively short, calcified, or angled neck of theaorta that is one of the most frequent reasons why the endovasculartreatment is ruled out for patients.

The problems of the endovascular technique have been observed over thepassage of time, and are associated with the intrinsic nature of theproduct and the implantation technique, migration of the prosthesis, thebreakage of the metal parts due to stress corrosion, or loss of sealwith refill of the aneurysm (referred to as endo-leak) and ultimatelyrupture some distance away. “Refill” of the aneurysm may occur eitherthrough loss of contact of the prosthesis with the arterial wall orthrough disconnection of its parts, and, also and more frequently, it isdue to the persistent patency of the lumbar arteries. In addition to theneed for further surgery with additional corrections, or even removal ofthe endoprosthesis and repair through delayed conventional procedures,these problems make it necessary to subject all surgery patients toundergo periodical checks (a CT scan every 6 months) for the rest oftheir lives. In a search for alternative techniques of a mini-invasivenature that, nevertheless, guarantee the same efficiency and durabilityas the conventional procedure, a laparoscopic technique that combinesthe good results of implanting conventional prostheses, with reducedtrauma in comparison with the conventional technique, has been developedquite recently. In fact, the laparoscopic technique makes it possible toopen the aorta, suture the lumbar arteries, and “sew on” conventionalprostheses, which, therefore, provide a guaranteed seal. Such atechnique does not involve any, or only minimum, cutting of the abdomen,over a length of a few centimeters, obtaining access to the abdomenthrough simple “holes” through which optic fibers, to provide a videoview of the site of the operation, or “ad hoc” constructed instruments,are passed. Although such a technique resolves the problems ofinvasiveness, in that, patients can have a very short convalescence andnegligible inconvenience, there are, nevertheless, a number oflimitations associated with the longer duration of the procedure, due tothe difficulty of operating in restricted spaces. In addition, to beable to restrict the incision (laparotomy) to only 7 to 8 centimeters,there is a technical difficulty in gaining access to the iliac arteries,to which the two limbs of the prosthesis are sutured.

SUMMARY OF THE INVENTION

It is accordingly an object of the invention to provide a vascularprosthesis implanted using a combined laparoscopic/open and endovasculartechnique for curing aneurysms of the abdominal aorta and deliverysystem for releasing a prosthesis fitted with anchoring stents thatovercome the hereinafore-mentioned disadvantages of the heretofore-knowndevices and methods of this general type and that provides a vascularprosthesis that can be implanted through a mini-laparatomy and, thus,with reduced invasiveness, that provides a vascular prosthesis havingiliac branches with stents that can be inserted in the iliac arteriesfrom inside the opened aortic aneurysm, pulled from the femoralarteries, and endovascularly sealed to the iliac arteries by inflatingthe two balloons inside the stents, thus, reducing the times forisolation of the iliac arteries and suture of the branches.

With the foregoing and other objects in view, there is provided, inaccordance with the invention, a bifurcated vascular prosthesis forimplantation through a combined laparoscopic/open and endovasculartechnique for curing aneurysms of the abdominal aorta, including atubular body having a lower extremity and an upper proximal extremity tobe sutured to a proximal neck of the aorta, a pair of tubular branchesdiverging downwards from the lower extremity of the body and ending incorresponding distal portions, the tubular body and the tubular branchesbeing of a vascularly usable material, and retaining members secured tothe distal portions.

In accordance with another feature of the invention, the retainingmembers are two stents. Each of the stents can be formed of a tubularportion of expandable metal mesh of a biocompatible material. Each ofthe stents can be fixed respectively within each extremity of the distalportions and can be at least partly covered by the material.

With the objects of the invention in view, there is also provided abifurcated vascular prosthesis for implantation through a combinedlaparoscopic/open and endovascular technique for curing aneurysms of theabdominal aorta, including a Y-shaped prosthesis body of a materialusable in animal vessels having a body portion with a lower extremityand an upper extremity to be sutured to a proximal neck of the aorta anda tubular branches respectively diverging away from the lower extremityand ending in corresponding distal portions, and retaining memberssecured to the distal portions.

With the objects of the invention in view, there is also provided adelivery system for the release of a prosthesis fitted with anchoringstents including:

-   -   a pair of releasing balloon catheters each having a small tube        with two opposite ends, one end of the small tube being provided        with a balloon intended to be inserted within the corresponding        stents of the vascular prosthesis and to remain adhering thereto        throughout the time prior to release, and the opposite end of        the small tube being provided with a portion suitable for        connecting to an inflating syringe;    -   a pair of inflating syringes provided with a connection to the        release catheter for inflating the balloons to achieve release        of the stents;    -   a pair of guiding balloon catheters each including a dilator and        a sheath;        -   the dilator, which has an inner lumen with a diameter            suitable for passage of the small tube of the releasing            catheter, having a proximal portion, a median portion, and a            distal portion, the proximal portion, of larger outside            diameter, being provided with a haemostatic valve, the            median portion having a constant outside diameter less than            that of the proximal portion, and the elongated distal            portion tapering for retrieval in the aorta; and        -   the sheath being a tubular member with an inside diameter            slightly greater than that of the median portion of the            dilator and having an outer terminal balloon corresponding            to a distal end thereof, the balloon being connected to a            small tube running outside and eccentrically with respect to            the tubular member and terminating in a portion suitable for            connecting to an inflating syringe; and    -   conventional valved introducers for each balloon guide catheter.

With the objects of the invention in view, there is also provided adelivery system for release of a prosthesis having anchoring stents,including a pair of releasing balloon catheters each having aninflatable balloon adapted to be removably inserted within a portion ofthe prosthesis, a self-supporting tube defining a lumen and having afirst diameter and two opposing ends, a cup connection having a seconddiameter greater than the first diameter, the cup connection beingdisposed at a first of the ends and connecting the inflatable balloon tothe tube for fluidically connecting the lumen with the inflatableballoon to pass liquid to inflate the inflatable balloon, and a terminalconnection fluidically connected to the lumen at a second of the ends, apair of inflating syringes each having a connection for releasableattachment to the terminal connection of a respective one of thereleasing catheters and, when connected thereto, fluidically connectinga respective one of the syringes to the inflatable balloon, a pair ofguiding balloon catheters each having a dilator defining an inner lumenhaving an inside third diameter sized to pass the tube of the releasecatheter therethrough, the dilator having a proximal portion having anoutside fourth diameter larger than the third diameter, a median portionhaving a constant outside fifth diameter smaller than the outside fourthdiameter, and a distal portion tapering for insertion into a vessel, anda tubular sheath having distal ends, an inside sixth diameter at leastas great as the outside fifth diameter of the median portion of thedilator and less than the second diameter of the cup connection, asecond tube extending away from the sheath and terminating in a portionsuitable for connecting to one of the inflating syringes, and a terminalouter balloon connected to the second tube, the terminal outer balloonbeing disposed at one of the distal ends of the sheath, and introducersfor introducing each of the balloon guide catheters into a patient.

In accordance with a further feature of the invention, the releasingcatheters have a set of hooks adapted to be captured withincorresponding stent cells of the vascular prosthesis and to remainadhering thereto throughout a time preceding inflation of the inflatableballoon.

In accordance with an added feature of the invention, each of thereleasing catheters have a set of hooks corresponding to a shape of theinflatable balloon and hooks are adapted to be inserted within acorresponding stent of the vascular prosthesis and to remain adheringthereto throughout a time preceding inflation of the inflatable balloonfor release.

In accordance with an additional feature of the invention, each of therelease catheters has a set of hooks adapted to be inserted within acorresponding stent of the vascular prosthesis for adhering the hooks tothe prosthesis.

In accordance with yet another feature of the invention, at least one ofthe tubes of the releasing catheters is threaded and the connection ofat least one of the inflating syringes is correspondingly threaded forconnection to the at least one tube.

In accordance with yet a further feature of the invention, the sheath isexternally marked, preferably, in centimeters and, in particular, withmillimeters as well.

In accordance with yet an added feature of the invention, the sheath hasa selective moving ring system adapted to be immobilized on a respectiveone of the introducers.

In accordance with yet an additional feature of the invention, thesheath has an immobilizer locking the sheath on a respective one of theintroducers.

With the objects of the invention in view, there is also provided amethod for releasing an aortic prosthesis, including the steps ofpositioning an introducer in femoral arteries of a patient, providingguiding catheters with depth graduations and balloons, positioning theguiding catheters through the introducers to locate the balloons interminal parts of common iliac arteries, clamping the proximal aorta,inflating the balloons of the balloon guiding catheters, and opening theaorta, in particular, the aneurysm, accessing from outside the vessel,threading distal ends of the releasing balloon catheters through theguiding catheters and recovering the distal ends of the releasingcatheters outside the patient, removing the dilators, moving theprosthesis until distal portions of the releasing catheters contact theguiding catheters, suturing a proximal part of the prosthesis to theaorta, inflating the balloons of the releasing catheters to fix thedistal portions of the prosthesis, deflating and extracting thereleasing catheters, deflating the balloons of the guiding catheters andremoving the guiding catheters, suturing the aorta, in particular, theaneurysm sack, and removing the introducers.

In accordance with again another mode of the invention, guide wires areintroduced through the introducers.

In accordance with again a further mode of the invention, a position ofthe guiding catheters is maintained with the depth graduations viewed onthe outside of the introducers.

In accordance with again an added mode of the invention, the releasingcatheter threading step is carried out by inserting distal ends ofdilators through the guiding catheters, threading the distal ends of thereleasing catheters through lumen of the dilators and recovering thedistal ends of the releasing catheters outside the patient, and removingthe dilators.

In accordance with again an additional mode of the invention, a distancebetween at least one tip of the dilators and a point foraorto-prosthetic anastomosis is calculated and a length of the vascularprosthesis to be implanted is determined thereby.

In accordance with still another mode of the invention, prosthesisproximal surplus is cut off based upon the length determined.

In accordance with still a further mode of the invention, the aortaincising and suturing steps are carried out by incising and suturing theaneurysm of the aorta.

In accordance with still an added mode of the invention, anchoringstents are disposed at distal portions of the prosthesis and thedeployment step is carried out by inflating balloons of the releasingballoon catheters within the stents.

In accordance with an additional mode of the invention, the moving stepis carried out by pulling the releasing catheters until the distalportions of the releasing catheters approximately abut against distalends of the guiding catheters.

In accordance with a concomitant mode of the invention, the lumbararteries are closed off at the opening of the aorta

All in all, the present invention is configured to provide a vascularprosthesis that can be used through a combined laparoscopic/open andendovascular technique. This combined technique is based on the findingthat:

-   -   conventional suturing of the prosthesis to the “proximal neck”        is currently the safest and most provenly effective method for        preventing migration of the prosthesis;    -   the laparoscopic technique reduces invasion and makes it        possible to suture a bifurcated prosthesis to the proximal neck        of the aorta and suture the lumbar arteries, thus eliminating        the problems associated with current traditional techniques; and    -   in the endovascular technique, few complications arise with the        sealing of a bifurcated aortic endoprosthesis to the iliac        branches.

The device, system, kit, and method of the present invention are notlimited to the laparoscopic surgery approach. All fit well andproductively within all the new techniques of minimally invasive opensurgery.

Other features and modes that are considered as characteristic for theinvention are set forth in the appended claims.

Although the invention is illustrated and described herein as embodiedin a method for implanting a vascular prosthesis for the treatment ofabdominal aortic aneurysms, using a combined laparoscopic/open andendovascular technique and delivery system for releasing a prosthesisfitted with anchoring stents, it is, nevertheless, not intended to belimited to the details shown because various modifications andstructural changes may be made therein without departing from the spiritof the invention and within the scope and range of equivalents of theclaims.

The construction and method of operation of the invention, however,together with additional objects and advantages thereof, will be bestunderstood from the following description of specific embodiments whenread in connection with the accompanying drawings.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a fragmentary, perspective view of a vascular prosthesis forabdominal aortic aneurysm according to the invention;

FIG. 2 is a fragmentary, exploded perspective view of a releasingballoon catheter and a syringe in the delivery system according to theinvention;

FIG. 3 is a fragmentary, exploded perspective view of the vascularprosthesis of FIG. 1 connected to a pair of the releasing catheters andsyringes of FIG. 2;

FIG. 4 is a perspective view of a guiding balloon catheter, including aconventional valve introducer, forming part of the delivery system kitaccording to the invention;

FIG. 5 is a fragmentary, side elevational view of an alternativeembodiment of the releasing balloon catheter according to the invention;

FIGS. 6 to 12 are fragmentary, perspective diagrammatical views of ananeurysm of the abdominal aorta during successive stages of implantationof the prosthesis of FIG. 1 in a method according to the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

Referring now to the figures of the drawings in detail and first,particularly to FIG. 1 thereof, there is shown the general appearance ofa vascular prosthesis for curing aneurysms of the abdominal aorta,indicated as a whole by reference numeral 100. The prosthesis 100 has ashape of an upside-down Y and includes a tubular body 102 and a pair oftubular branches 111 and 112 diverging downwards from a lower end (notindicated by a reference number) of the tubular body 102. As illustratedin FIG. 1, tubular branches 111, 112 have a diameter smaller than thatof body 102, in that, the tubular branches 111, 112 are intended to bereceived within the iliac arteries, while the body 102 is receivedwithin the abdominal aorta at the location of an aneurysm, as will beillustrated below with reference to FIGS. 5 to 10. In particular,tubular body 102 has an upper proximal end 101 that is to be sutured tothe proximal neck of the aorta.

Downwardly diverging tubular branches 111, 112 terminate incorresponding distal extremities or portions 113, 114. The prosthesis isconstructed of a fabric suitable for vascular use such as DACRON®.

According to the invention, two stents 115, 116, or expandable anchoringsystems for holding the prosthesis, are secured to the distal portions113, 114.

In a conventional way, each stent 115, 116 includes a tubular portion ofexpandable metal mesh made of a biocompatible material. Each stent 115,116 is secured to the interior of each distal extremity 113, 114 ofbranches 111, 112 to be partly covered by the tissue of the prosthesis.In a preferred embodiment, the stent projects by half its length. Thestents, of predetermined maximum dimensions (when expanded), are securedto the fabric of branches 111, 112 by suturing or by other measures topermit “crimping” (compression) against a balloon portion of a releasingcatheter, as will be discussed below.

In a second aspect, the invention describes a delivery system forreleasing a vascular prosthesis as described above to cure an abdominalaortic aneurysm or other vascular and non-vascular prostheses fittedwith anchoring stents.

FIG. 2 shows a side view of a releasing balloon catheter 1 and pressuresyringe 10. Releasing catheter 1 has a self-supporting small tube 11with a single lumen for the passage of liquid for inflating the balloonand two opposing ends 12, 18. At end 12 there is a balloon 13 connectedto the tube 11 through a cup connection 14 terminating in a head 15.Each balloon 13 is intended to be inserted within a corresponding stent115, 116 of the vascular prosthesis and to remain adhering theretothroughout the time prior to prosthesis release. A threaded connectionis provided at end 18 opposite balloon 13.

Pressure syringe 10 fitted with pressure gauge 19 to achieve controlledinflation of balloon 13 of releasing catheter 1 can be connected to thethreaded connection through a correspondingly threaded connection 17.However, connection between the distal portion of small tube 11 andconnection 17 of the syringe may be other than by a threaded connection.The releasing catheters come from manufacturers already engaged with theexpandable portion of the prosthesis. Any aspect of the delivery systemcould be sold in separate pieces, but, preferably, the system of thepresent invention includes the syringes and guiding catheters. In thesystem for the implantation of prosthesis 100 there is one pair ofsyringes 10. See, i.e., FIG. 3.

Releasing catheter 1 is associated with prosthesis 100 through itsballoon 13 within the corresponding stents 115, 116 of prosthesis 100such that there is structural continuity between catheter 1 andprosthesis 100. In fact, catheter 1 and branches 113, 114 of prosthesis100 become one piece through the effect of compressing the stent 115,116 against the balloon 13 of the catheter 1.

In a variant illustrated in FIG. 5, which is a partial frontal view of areleasing catheter 5, provision is made for a series of hooks 50incorporated with the cup connection for balloon 54, for example,through a sheath 51 on which they are hinged. Hooks 50, which can numberthree or four, made of a material similar to that of the catheter, havepoints facing inward and are intended to engage the mesh of the stentcompressed on balloon 54. Hooks 50 may act as an aid to prevent theballoon 54 from being drawn along by the stent during traction, adheringto the mesh of the stent 115, 116. Of course, hooks 50 will cease toengage the stent 115, 116 when the balloon 54 is inflated and deflatedfor release of the prosthesis 100.

At rest, and, therefore, in a closed conformation, the stents 115, 116are compressed onto the balloons 13, 54 of the balloon catheters 1, 5.For such a purpose, the length of the stent 115, 116 corresponds to thelength of the isometric portion of the balloon as shown in FIG. 3.

The small tube 11 of the releasing balloon catheter 1 has an externaldiameter D1 e (FIG. 2), while its cup connection 14 with balloon 13 hasa diameter D1, again measured externally. Diameter D1 is greater thandiameter D1 e.

The tube 11 of releasing catheter 1 (preferably, of a conventionalplastic material) allows the liquid filling balloon 13 to passtherethrough and to inflate the balloon 13 under pressure. In theproximal portion corresponding to the balloon 13, the cup connection 14has a shoulder with an outer diameter D1, for example, approximatelyequal to 2 mm. This diameter is substantially identical to diameter D3 i(see FIG. 4) to form an abutting contact. The small tube 11 has anexternal diameter D1 e of approximately 1.35 mm and a length ofapproximately 0.60 to 1.5 m, by way of example.

With reference to FIG. 4, three components of the delivery system areillustrated that have a function of guiding the releasing ballooncatheter, together with guiding wires and syringes not illustrated inFIG. 4. In particular, FIG. 4 shows a guiding balloon catheter includinga dilator 2 and a sheath 3. The guiding catheter works in a conventionalintroducer 4.

Dilator 2 has a tubular structure with a proximal portion 20, a medianportion 21, and a distal portion 22. Proximal portion 20, which has alarger outside diameter D2 v, is provided with a haemostatic valve.Median portion 21 has a constant outside diameter D2 e that is less thanthat of proximal portion D2 v, while distal portion 22, which is taperedand elongated for entry into the aorta and to reach the aneurysmaticportion, has a minimum diameter D2 d.

Dilator 2 has an inner lumen of diameter D2 i that is suitable forpassage of the small tube 11 of the releasing catheter 1 (which has anoutside diameter D1 e, for example of 1.35 mm, as mentioned above).

Sheath 3 is external and supplementary to median portion 21 of dilator2, as a result, the dilator 2 projects from the sheath by some 10 to 15cm. The sheath 3 is made of a suitable plastic material and has theshape of a tube 30 of maximum outside diameter D3 e. Sheath 3 has acentral channel 31 of inside diameter D3 i suitable for the passage ofdilator 2 and substantially identical to the diameter D1 of thereleasing catheter 1, and an eccentric channel 32 for inflating aballoon 33 located at the distal end of sheath 3. Balloon 33 can beinflated by liquid and is made of a compliant plastic material ofapproximately one centimeter's length. When inflated, balloon 33 takesup an elliptical shape, with a major diameter D3 e that is transverse tothe axis of sheath 3 and that varies, for example, from 10 mm to 14 mm.The distal part of balloon 33 is located approximately 2 mm from the endof sheath 3. The liquid is delivered to balloon 33 through the eccentricchannel 32 that terminates at the proximal extremity in a syringeconnection 34. The outside of the sheath 3 is graduated in centimeters,i.e., it is notched and/or numbered so that the depth to which it isintroduced can be determined, as will be discussed below. Forconvenience in use, a movable ring with an immobilizing system 35 of thetraditional spring-loaded ratchet type may be present on the outside ofthe sheath to mark the point at which the sheath 3 exits from introducer4.

The guiding balloon catheter complex including dilator 2 and sheath 3 iscompatible with a conventional introducer 4 of suitable size.

Introducer 4 has an inside diameter D4 i, conventionally of 7 French(2.3 mm), to allow the passage of the sheath 3 having a slightly smalleroutside diameter D3 e. Sheath 3 has an inside diameter D3 i, for exampleof 2 mm, to allow dilator 2 having a diameter D2 e, which is slightlyless than the inside diameter D3 i of the sheath, to pass. As alreadymentioned, within dilator 2 there is a constant lumen of diameter D2 ithat is slightly greater than the outside diameter D1 of small tube 11of the releasing catheter 1.

An example of the release of the vascular prosthesis 100 according tothe present invention through the use of the delivery system includingreleasing balloon catheters 1 and guiding catheters (dilator 2, sheath3) and the surgical kit including the syringes and introducers and,possibly, the prosthesis 100 as well, according to the present inventionis provided below with reference to FIGS. 6 to 12, which arediagrammatical views of a region where the prosthesis 100 is releasedand the corresponding system. Release is made possible by a combinedlaparoscopic/open and endovascular technique for curing aneurysms of theabdominal aorta developed by the inventors of the present invention.

Prosthesis 100 is configured to be introduced through a small incisionin a patient's abdomen. The proximal part of prosthesis 100 is cut offaccording to need and measurements taken “in vivo” and from tomographyscans.

FIGS. 6 to 12 diagrammatically show the abdominal aorta affected by ananeurysm A below the proximal neck C of the aorta. AC indicates thecommon iliac artery, AE the external iliac artery, AF the femoralartery, and AI the hypogastric arteries.

As shown in FIG. 6, conventional introducers 4, fitted with valves, arepositioned by percutaneous puncture of the femoral arteries AF. Throughthe introducers 4, non-illustrated guide wires are introduced with thehelp of radioscopy. Guiding catheters 3 with balloons 33 are positionedon the introducers 4 such that the balloons 33 are located in theterminal parts of the common iliac arteries AC. The corresponding numberthat can be seen on the outside of introducer 4 in such a position ismarked, which makes it possible to maintain the correct positionthroughout the procedure without the need for radiological monitoring(see FIG. 6). The proximal aorta is clamped and balloons 33 of guidingcatheters 3 are inflated.

At the opening of the aorta, as shown in FIG. 7, the lumbar arteries areclosed off and the ends of dilators 2 are inserted. Because they are ofa fixed length, the distance between their tips and a suitable point foraorto-prosthetic anastomosis can be calculated, and, thus, the necessarylength of the vascular prosthesis can be determined and the surplus atthe proximal end can be cut off. As an alternative, small tubes 11 arefitted onto the tapering distal portions 22 of dilators 2 (FIG. 7),recovering them outside the patient, dilators 2 are extracted (FIG. 8)and the prosthesis 100 is moved until it comes to a stop through contactbetween the cup 14 of the releasing catheters 1 and the distal ends ofthe guiding catheters 3, and, then, the surplus proximal part of theprosthesis 100 is cut off. The proximal part of the prosthesis 100 is,then, sutured to the proximal neck C of the aorta using conventionalmethods (FIG. 9), where numeral 6 indicates needles for suturing orwhere suturing will be performed in the future, with automatic staplers,for example.

Once the anastomosis has been completed and its leaktightness has beenchecked, if this has not been done previously, the distal ends of thereleasing catheters 1 are introduced into the lumens of the guidingcatheters, removed to the exterior and recovered, and dilators 2 areextracted from them (FIG. 8). Then, the ends of the two releasingcatheters 1 are carefully pulled until cup connections 14 of thereleasing catheter 1 abut against the ends of sheath 3 of the guidingcatheters (FIG. 10). The terminal portions 18 of catheters 1 are screwedinto connections 17 of syringes 10 with pressure gauges, balloons 13 ofreleasing catheters 1 are inflated and, thereafter, the stents 115, 116are released (FIG. 11).

At this point balloons 13 are deflated, balloon catheters 1 areextracted, and, then, balloons 33 are deflated and the sheaths 3 of theguiding catheters are withdrawn. A check is made to ensure that thestents 115, 116 are correctly positioned and that they are leaktight,and, then, suturing S of the aneurysm part A of the aorta is performed(FIG. 12). Upon completion, an angiographic check can be performed andintroducers 4 in the femoral arteries can be removed.

Using the combined laparoscopic/open and endovascular techniquedescribed above, which is made possible by the present invention, theproblems associated with conventional surgery and the complications andconsequences of a long median abdominal incision, such as post-operativepain, dynamic ileum (lack of digestive movements of the intestine for4-5 days), immobility, and respiratory complications are mitigated.

Using the technique described above, which is made possible by thepresent invention, problems that may follow the mere endovascularexclusion of aneurysms of the abdominal aorta can also be overcome. Theproblems overcome include:

-   -   migration of the prosthesis as a result of its suture to the        stump of the aorta;    -   endo-leaks due to loss of seal at the proximal supporting points        (Type I) because of the proximal surgical suture and the low        probability of movement and loss of adhesion of the stents in        the iliac arteries;    -   endo-leaks due to all the arteries that might give rise to        reflux bleeding (lumbar and inferior mesenteric arteries) (Type        II), given that these arteries are sutured directly;    -   endo-leaks due to disconnection (Type III) of the various        modules, as this is a single body prosthesis;    -   the need for large introducers for femoral access, it being        possible to perform the endovascular part wholly percutaneously        (i.e., without incision); and    -   reduced exposure to radiation, in that, the presence of        centimeter-graduated guiding catheters makes it possible to        position the catheters under radiological guidance once only, at        the start of the procedure, and positioning of the distal part        of the prosthesis can be completed merely by nesting the        releasing catheters in the guiding catheter sheaths (of the same        diameter).

Using the technique described above, made possible by the presentinvention, problems associated with the laparoscopic technique alone,such as the elimination of sutures in the iliac branches and thepossibility of making a single anastomosis, which appreciably reducesthe time required for the reconstructive stage of surgery, are alsoovercome.

The prosthesis according to the invention will be made in various sizes,with various stent diameters (as regards the measurement of maximumexpansion) and various balloon diameters for the releasing catheter,according to the requirements of the patient for whom it is intended.

The present invention has been described with reference to a specificembodiment, but it must be expressly understood that modifications,admissions, and/or omissions may be made without thereby going beyondthe corresponding scope of the protection defined by the appendedclaims.

1. A method for releasing an aortic prosthesis, which comprises:positioning an introducer in femoral arteries of a patient; providingguiding balloon catheters with depth graduations and balloons;positioning the guiding catheters through the introducers to locate theballoons in terminal parts of common iliac arteries; clamping theproximal aorta, inflating the balloons of the guiding catheters, andopening the aorta for access from outside the vessel; threading distalends of releasing balloon catheters through the guiding catheters andrecovering the distal ends of the release catheters outside the patient;connecting distal ends of releasing catheters to distal portions of aprosthesis; moving the prosthesis until distal portions of the releasingcatheters contact the guiding catheters; suturing a proximal part of theprosthesis to the aorta; inflating the balloons of the releasingcatheters to fix the distal portions of the prosthesis; deflating theballoons of the releasing catheters and removing the releasingcatheters; deflating the balloons of the guiding catheters and removingthe guiding catheters; suturing the aorta; and removing the introducers.2. The method according to claim 1, which further comprises introducingguide wires through the introducers.
 3. The method according to claim 1,which further comprises maintaining a position of the guiding catheterswith the depth graduations viewed on the outside of the introducers. 4.The method according to claim 1, which further comprises carrying outthe releasing catheter threading step by: inserting distal ends ofdilators through the guiding catheters; threading the distal ends of thereleasing catheters through lumen of the dilators and recovering thedistal ends of the releasing catheters outside the patient; and removingthe dilators.
 5. The method according to claim 4, which furthercomprises calculating a distance between at least one tip of thedilators and a point for aorto-prosthetic anastomosis and, thereby,determining a length of the vascular prosthesis to be implanted.
 6. Themethod according to claim 5, which further comprises cutting offprosthesis proximal surplus based upon the length determined.
 7. Themethod according to claim 1, which further comprises: carrying out theaorta incising step by incising the aneurysm of the aorta; and carryingout the aorta suturing step by suturing the aneurysm of the aorta. 8.The method according to claim 1, which further comprises: disposinganchoring stents at distal portions of the prosthesis; and carrying outthe connecting step by inflating balloons of the releasing catheterswithin the stents.
 9. The method according to claim 1, which furthercomprises carrying out the moving step by pulling the releasingcatheters until the distal portions of the releasing cathetersapproximately abut against distal ends of the guiding catheters.
 10. Themethod according to claim 1, which further comprises closing off thelumbar arteries at the opening of the aorta.
 11. A method for releasingan aortic prosthesis, which comprises: locating balloons of guidingballoon catheters in terminal parts of each of the common iliacarteries; opening the aorta for access from outside the vessel;threading distal ends of releasing balloon catheters through the openedaorta and the upstream openings of the guiding balloon catheters andrecovering the distal ends of the releasing balloon catheters outsidethe patient; releasably connecting distal ends of the releasing ballooncatheters to respective distal ends of a bifurcated tubular prosthesis;moving the distal end of the bifurcated tubular prosthesis through theopened aorta towards the common iliac arteries with the releasingballoon catheters until distal portions of the prosthesis are adjacentthe guiding balloon catheters; fluidically connecting a proximal openingof the prosthesis to the aorta; and fixing the distal portions of theprosthesis in a respective one of the common iliac arteries with theballoons of the releasing balloon catheters.
 12. The method according toclaim 11, which further comprises, after carrying out the distal portionfixing step: removing the releasing balloon catheters; removing theguiding balloon catheters; closing the opened aorta.
 13. The methodaccording to claim 11, which further comprises carrying out the locatingstep by introducing the guiding balloon catheters through introducersrespectively placed in the femoral arteries of a patient.
 14. The methodaccording to claim 11, which further comprises, prior to opening theaorta, clamping the proximal aorta and inflating the balloons of theguiding balloon catheters.
 15. The method according to claim 13, whichfurther comprises recovering the distal ends of the release cathetersoutside the patient at downstream openings of the introducers.
 16. Themethod according to claim 11, which further comprises carrying out themoving step by moving the bifurcated tubular prosthesis through theopened aorta towards the common iliac arteries until distal portions ofthe releasing balloon catheters contact the guiding balloon catheters.17. The method according to claim 11, which further comprises carryingout the fixing step by inflating the balloons of the releasing ballooncatheters within the distal portions of the prosthesis.
 18. The methodaccording to claim 12, which further comprises: before removing thereleasing balloon catheters, deflating the balloons of the releasingcatheters; and before removing the guiding balloon catheters, deflatingthe balloons of the guiding balloon catheters.
 19. The method accordingto claim 13, which further comprises removing the introducers afterremoving the releasing balloon catheters and the guiding ballooncatheters.
 20. The method according to claim 11, which further comprisescarrying out the threading step by: inserting distal ends of dilatorsthrough the guiding balloon catheters; threading the distal ends of thereleasing balloon catheters through lumen of the dilators and recoveringthe distal ends of the releasing catheters outside the patient; andremoving the dilators.
 21. The method according to claim 20, whichfurther comprises calculating a distance between at least one tip of thedilators and a point for aorto-prosthetic anastomosis and, thereby,determining a length of the vascular prosthesis to be implanted.
 22. Themethod according to claim 21, which further comprises cutting offprosthesis proximal surplus based upon the length determined.
 23. Themethod according to claim 12, which further comprises: carrying out theaorta opening step by incising the aneurysm of the aorta; and carryingout the aorta closing step by suturing the aneurysm of the aorta. 24.The method according to claim 11, which further comprises: disposinganchoring stents at distal portions of the prosthesis; and carrying outthe fixing step by inflating balloons of the releasing catheters withinthe stents.
 25. A method for releasing an aortic prosthesis, whichcomprises: positioning introducers respectively in femoral arteries of apatient; threading guiding balloon catheters through the introducers tolocate balloons of the guiding balloon catheters in terminal parts ofcommon iliac arteries; clamping the proximal aorta, inflating theballoons of the guiding balloon catheters, and opening the aorta foraccess from outside the vessel; threading distal ends of releasingballoon catheters through the guiding balloon catheters and recoveringthe distal ends of the releasing balloon catheters outside the patient;releasably connecting the distal ends of the releasing balloon cathetersto distal portions of a bifurcated tubular prosthesis; moving theprosthesis with the releasing balloon catheters until distal portions ofthe releasing balloon catheters are adjacent the guiding ballooncatheters; fluidically connecting a proximal opening of the prosthesisto the aorta; inflating the balloons of the releasing balloon cathetersto fix the distal portions of the prosthesis; deflating the balloons ofthe releasing balloon catheters and removing the releasing ballooncatheters; deflating the balloons of the guiding balloon catheters andremoving the guiding balloon catheters; suturing the aorta; and removingthe introducers.